[Whitebread]

Hi guys, are they're any DIY preamp designs out there? All the stereo preamps are super expensive and way out of my price range. I'd have no preference for active or passive, I just want to see if there are any designs avaliable.

 

[blueworm]

It has been reported on this forum that the dynalo and the millet hybrid perform rather well as pre-amps.
I can confirm that the millet performs well since I use it as a preamp for a gainclone power amp.

 

[rickcr42]

Just about every single headphone amp here is no more than a preamp with good current drive.Pick one,add an input selector and jacks then a headphones/line output switch and save yourself a bundle of loot and/or hassle.

there is zero reason many times to have both a preamp AND a headphone amp in the same system if it is only a single system you use for all things

 

[americandreaming]

the kookaburra should not be out of range of your budget. very good things are said about the performance over at diyaudio, and i can vouch that the quality of the kit and the support from russ and brian are excellent.

 

[Whitebread]

Quote:

Originally Posted by rickcr42 Just about every single headphone amp here is no more than a preamp with good current drive.Pick one,add an input selector and jacks then a headphones/line output switch and save yourself a bundle of loot and/or hassle. there is zero reason many times to have both a preamp AND a headphone amp in the same system if it is only a single system you use for all things

The problem is that I have speakers and multiple sources. And if I get serious about Vinyl, I may get an EMU and start recording the vinyls onto my PC. If I just was using headphones, I'd add some jacks and an input selector and be done with it, but I have, at least 3 sources, headphones, speakers and a subwoofer.

 

[Whitebread]

Quote:

Originally Posted by americandreaming the kookaburra should not be out of range of your budget. very good things are said about the performance over at diyaudio, and i can vouch that the quality of the kit and the support from russ and brian are excellent.

Thanks, i'll look.

 

[Whitebread]

Quote:

Originally Posted by blueworm It has been reported on this forum that the dynalo and the millet hybrid perform rather well as pre-amps. I can confirm that the millet performs well since I use it as a preamp for a gainclone power amp.

Thanks, but I dont want to use an amp as a pre-amp when I'm going to be buidling an M3.

 

[blueworm]

Ok how about something like this passive pre-amp.
http://kotiweb.kotiportti.fi/audiovideo/DIY/preamp1/

 

[amb]

Quote:

Originally Posted by Whitebread Thanks, but I dont want to use an amp as a pre-amp when I'm going to be buidling an M3.

You don't need a separate preamp. Just add a stereo source selector switch for multiple inputs to your M³, and add loop-out or preamp-outs for driving external speaker power amps. The "Other options" section of the M³ website has info about these configurations.

 

[Whitebread]

Quote:

Originally Posted by blueworm Ok how about something like this passive pre-amp. http://kotiweb.kotiportti.fi/audiovideo/DIY/preamp1/

Yep, that's great, I was looking for something like that.

 

[Whitebread]

Quote:

Originally Posted by amb You don't need a separate preamp. Just add a stereo source selector switch for multiple inputs to your M³, and add loop-out or preamp-outs for driving external speaker power amps. The "Other options" section of the M³ website has info about these configurations.

O, well I didn't know that. I will look into this as well as that passive preamp link. I'm sure they are similar, but we'll see. Thanks a ton guys.

 

[rickcr42]

Quote:

but I have, at least 3 sources, headphones, speakers and a subwoofer.

three position rotary selector.no reason to overcomplicate the simple and having two gain stages where one will do is definately not only overcomplicating but tossing money away for no good reason.

Already have a headphone preamp ?

Simple add-on exterior box :

Switch #1-Input Select Rotary (with "Rec Out" tap.also known as "loop out")
Switch #2-Tape monitor/Input Select (DPDT Switch)
Switch #3-Output Select Rotary Switch

way better for the price than an entiely new preamp when the circuit,power upply and casing is added up.If your headphone amp is one of those three channel amps then just use a four pole selector switch on the output section.

 

[blueworm]

Here is waht the back of my setup looks.

line out on millet to gainclone.

 

[Whitebread]

Quote:

Originally Posted by rickcr42 three position rotary selector.no reason to overcomplicate the simple and having two gain stages where one will do is definately not only overcomplicating but tossing money away for no good reason. Already have a headphone preamp ? Simple add-on exterior box : Switch #1-Input Select Rotary (with "Rec Out" tap.also known as "loop out") Switch #2-Tape monitor/Input Select (DPDT Switch) Switch #3-Output Select Rotary Switch way better for the price than an entiely new preamp when the circuit,power upply and casing is added up.If your headphone amp is one of those three channel amps then just use a four pole selector switch on the output section.

rickcr42,
3 things I don't understand, why is Rec Out included with the input select rotary switch, wouldn't that be grouped with output?
Why is switch 2 the tape monitor/input select switch? I guess I don't quite understand what a tape monitor is.
Where is the potentiometer or a stepped attenuator? The M3 already has a preamp, but I need something to control my power amp for the speakers
Will I need to switch +/- and ground if I am going to use the M3, or just the +/-?

I'm sorry about my inexperience, I am just trying to learn.

 

[rickcr42]

Quote:

3 things I don't understand, why is Rec Out included with the input select rotary switch, wouldn't that be grouped with output?

No,that would mean going through any gain stage and ALL record outputs to my knowledge are pure signal directly unless the control console is a very elaborate one having a separate record and play selector switch.This has more versatility but also puts a strain on the source so not always
better" even though it would seemigly be.

the simple answer is whatever is selected as the input appears at the record output.

Quote:

Why is switch 2 the tape monitor/input select switch? I guess I don't quite understand what a tape monitor is.

Because it allows for an entirely NEW input not effected by the input selector.Originally it was designed for three head tape recorders so you could send the signal being recorded to the deck from the REC OUT jack then monitor either what was being recorded directly to the tape (Tape Monitor) or the original signal GOING TO the deck by flipping back and forth without any intervening electronics being present so a pure state signal.

This "loop" turned out to be ideal for adding processing such as equalisers or dynamic range companders and so you see "E.P.L." many times on the same unit as the "Tape/Input Monitor" select switch.By flipping a switch either could be put in the signal path or taken 100% out.Since we no longer have analog tape machines used much for home recording (I do

) and any processing is considered "not cool" in audiophile circles many times this is now labled "Loop out/Loop in" which replaces the original "Tape out/Monitor in"

Quote:

Where is the potentiometer or a stepped attenuator? The M3 already has a preamp, but I need something to control my power amp for the speakers Will I need to switch +/- and ground if I am going to use the M3, or just the +/-?

The same volume control is used for everything just like it would be in a full feature preamp with a headphone output.Simply adjust the level for whatever it is you are presently listening too

Example :

If you put the M3 in the "Loop" you now have the ability to use it as either a headphone amp or preamp by selecting the monitor input while also having the ability to totally bypass the stage and send the input signal directly to the output jacks with no gain at all.This CAN be an unsafe condition if you inadvertantly flip the switch to "input" because you will be sending a FULL VOLUME signal directly from the input jacks to the output jack selected.If this is scary or you are the type who just may forget this then the easy workaround would be to add another "loop" for the M3 but this time with no "out" position so it is always in the path.


If your output are say three then you can have two rear panel RCA jack outputs and one fron panel headphone output and use this new "box" for all audio connections

Quote:

I'm sorry about my inexperience, I am just trying to learn.

don't be sorry man.We ALL had a beginning and needed to learn from either a book or another persons experience.I personally think real world experience trumps theory read in a book so do not mind taking the time to help those needing it.